It is proposed to set up a multifaceted, interdisciplinary program of research projects focusing on the field of reproductive endocrinology. This program will involve the coordinated efforts of 12 senior investigators in 6 University departments: Anatomy, Biological Chemistry, Obstetrics and Gynecology, Pathology, Pediatrics, and Zoology. The approaches involved will range from the cellular and molecular to the morphological and physiological, with extensive integration of the various levels. Major research emphasis will be placed on the following problems: brain-pituitary-ovarian endocrine maturation, regulation of gonadotropin secretion, localization of GnRH in hypothalamus, regulation of hypothalamic function by estradiol, estradiol action in corpus luteum, mechanism of gonadotropin action in tests, LH-receptors and ovarian function, and non-histone chromatin proteins and reproductive hormone action. Using our various types of expertise in exploring these problems in a variety of species, it is hoped to obtain a better understanding of reproductive endocrinology and physiology which can then form the basis for new approaches to contraception and population problems.